The following document has a Table 1 under section How do admissions officers use MCAT scores and other application data in the holistic review
of applicants’ qualifications?
https://www.aamc.org/system/files/c/1/498250-usingmcatdatain2020medstudentselection.pdf
Research/lab has a medium importance rating and selectivity of undergraduate institution has the lowest importance rating according to a survey of Admission Officers.